/Engine/Plugins/Experimental/ChaosCaching/Source/ChaosCaching/Public/Chaos/ChaosCache.h
Find the index the key where timestamp is directly above InCacheTime returned value is garanteed to be within the range of keys if there's any in the case there's no key in the track, 0 is returned
Valid key index
int32 GetUpperBoundEvaluationIndex ( float InCacheTime ) const